This invention relates to improvements in stunning guns used for the stunning of cattle.
The stunning guns that have been used in the past have been less than satisfactory in a number of respects, most notably in their lack of safety. Stunning guns typically include a bolt which is forcefully extended into the head of the animal when an explosive cartridge is fired by a trigger controlled firing pin. In guns which have a lever operated trigger, it is not uncommon for the operator to catch his finger between the lever and the gun body, thereby causing sometimes severe injury to the finger and hand area. Another safety problem is that the gun can fire and possibly cause injury if it is accidentially dropped or otherwise carelessly handled.
The stunning guns that have been used in the past are lacking somewhat in stunning power due to their inability to efficiently utilize the force of the exploding powder charge. When the cartridge explodes, the expanding gases can escape past the bolt and are not fully applied to cause extension of the bolt. Consequently, the bolt does not always extend with enough force to provide the necessary stunning power. The powder charge often burns incompletely, and this further detracts from the stunning power and also creates excess carbon residue and other fouling of the firing chamber. When the explosive force is not adequately confined, it causes rapid deterioration of the walls of the firing chamber and wear on the adjacent parts of the gun. This tendency for the parts to wear quickly reduces the operating life of the gun and requires replacement at frequent intervals.
The stunning guns that are currently used in the industry are difficult to maintain in good working order, due primarily to the time and difficulty involved in disassembling the gun for inspection and servicing of its various components. Problems with misfiring and jamming of cartridges make existing guns unreliable and slow down the entire operation. Also, shells are sometimes difficult to remove from the gun, particularly when the shell is jammed or misfired.
It is the principal goal of the present invention to provide a stunning gun which minimizes the safety problems and the operator and maintenance problems that have plagued other guns.
More specifically, it is an important object of the invention to provide a stunning gun in which the trigger mechanism is constructed in an improved manner to avoid catching on the fingers or otherwise injuring the fingers or hand of the operator. In contrast to guns having lever operated triggers, the gun of the present invention has a specially shaped push button trigger which does not catch the finger and yet can be easily and safely operated.
Another important object of the invention is to provide a stunning gun which makes efficient use of the force of an exploding cartridge to propel the bolt to its extended position. The bolt is equipped with a piston having a cupped recess in its end face which confines the force of the explosive charge and prevents it from spreading out unduly in the firing chamber. This results in effective application of the explosive force to the bolt and also prevents erosion of the firing chamber wall and adjacent parts. At the same time, the cupped shape of the recess creates swirling motion of the combustion gases to result in a more complete burn for enhanced efficiency and reduced build up of carbon and other undersirable deposits.
Still another object of the invention is to provide a stunning gun in which blows applied to the firing pin are safely absorbed.
A further object of the invention is to provide a stunning gun in which the bolt is firmly held in its retracted position and yet is not unduly hindered from extending when the gun is fired.
An additional object of the invention is to provide a stunning gun having a bolt which is able to easily penetrate even bony areas of an animal.
Yet another object of the invention is to provide a stunning gun in which the bolt is easily withdrawn from the animal and is not opposed in its return movement by excessive back pressure.
A still further object of the invention is to provide a stunning gun in which unfired and misfired cartridges can be quickly and easily removed from the firing chamber in a safe manner.
Other and further objects of the invention, together with the features of novelty appurtenant thereto, will appear in the course of the following description.